1. Field of the Invention
The present invention pertains to a waterproof mechanism that is suitable for cameras having a cartridge holder which houses a film cartridge so that the cartridge may be inserted into and removed from the camera body. The present invention also pertains to a sealing member used in the waterproof mechanism. The present invention further pertains to a camera including the waterproof mechanism.
2. Description of the Related Art
The conventional art related to the waterproof mechanism of the present invention is explained below using a camera as an example.
As a film insertion mechanism for a camera, a mechanism in which the insertion of film is completed by opening a rear cover of the camera to place a film cartridge in a prescribed position inside the camera, pulling the end of the film out of the cartridge so that the film will be engaged with the spool, and closing the rear cover to activate winding has been conventionally known. Waterproofing of the rear cover of the camera having such a film insertion mechanism using a rear cover is effected by mounting to the rear cover a ring-shaped rubber packing that covers the entire inside rim of the rear cover.
On the other hand, a mechanism has been proposed that has a tilt-type or slide-type cartridge holder, in which a film is automatically fed out from the cartridge and film insertion is completed by placing the cartridge in the cartridge holder which is removable from the camera body, and returning the cartridge holder to the camera body.
FIGS. 1 and 2 show perspective views of important components to outline the tilt-type cartridge holder. As shown in these drawings, cartridge holder 4 that houses a film cartridge may be moved from the housed position inside the camera body (the position shown in FIG. 1) to the cartridge reception/removal position (the position shown in FIG. 2) with pin 21 as the rotation shaft. In other words, at the cartridge reception/removal position shown in FIG. 2, cartridge insertion opening 41 formed on the top of cartridge holder 4 is exposed outside the camera body, and a film cartridge (not shown in the drawing) may be inserted into cartridge holder 4 from opening 41. When cartridge holder 4 housing a cartridge is moved with pin 21 as the rotation shaft back to the housed position shown in FIG. 1, the film inside the cartridge is automatically fed out from film outlet 43 and wound around the spool (not shown in the drawing), whereupon film insertion is completed.
As shown in FIG. 1, plate-shaped holder cover 6 is attached to cartridge holder 4. The holder cover 6 constitutes a part of exterior cover 1 of the entire camera when cartridge holder 4 is in the housed position, and moves together with cartridge holder 4 when cartridge holder 4 moves to the cartridge reception/removal position. In FIGS. 1 and 2, the positions of photo-taking lens 3, distance measurement window 22, finder window 23, shutter release button 24 and finder 25 are shown using chain lines.
On the other hand, a slide-type cartridge holder does not become tilted, but slides from a housed position in the camera body to a cartridge reception/removal position outside the camera body and vice versa.
In order to waterproof the tilt-type or slide-type cartridge holder like the rear cover in the rear cover-type film insertion mechanism described above, it is necessary to form an overlapping part at the border between the cartridge holder cover and the camera body, as well as to install a ring-shaped rubber packing that covers the entire rim of the overlapping part.
Incidentally, whether with the rear cover-type film insertion mechanism or with the film insertion mechanism using a tilt-type or slide-type cartridge holder, an increase in the number of manufacturing processes, such as the formation of a guide groove for correct positioning and the insertion of the ring-shaped packing in the guide groove, is inevitable in order to mount a ring-shaped rubber packing to a prescribed position. In addition, there are a number of other factors that lead to an increase in costs, including the need to use an adhesive to affix the packing.